add custom linkedin dev app guide

src/essentials-for-yootheme-pro/auths/custom-linkedin-dev-app.md

@@ -0,0 +1,78 @@
+# Custom LinkedIn Dev App
+
+Learn how to create a custom LinkedIn Developer App and generate the required access tokens to directly authenticate with Essential LinkedIn Sources.
+
+## Create LinkedIn App
+
+Sign in to the [LinkedIn Developer Portal](https://www.linkedin.com/developers) with your personal account. If you don't already have one, you can easily [create a free account](https://www.linkedin.com/).
+
+![LinkedIn Developer Portal](./assets/linkedin/ln-dev-portal.webp)
+
+Access [My Apps](https://www.linkedin.com/developers/apps) section and click on *Create App* button. Enter the required information and submit.
+
+![LinkedIn Create App](./assets/linkedin/ln-create-app.webp)
+
+| Setting | Description |
+| ------- | ----------- |
+| *App name* | The application name. Can be changed later. |
+| *App logo* | The application logo, can be the company one. |
+| *LinkedIn Page* | The associated LinkedIn Company Page URL, e.g. `https://www.linkedin.com/company`. |
+
+::: tip Company Page
+A LinkedIn App requires a LinkedIn Company Page to be associate with. Use your company's page or, if you're working for a client, their company page.
+
+Don't have a company page yet? No problem! Simply [create one here](https://www.linkedin.com/company/setup/new/).
+:::
+
+## Verify Page Association
+
+The organization that owns the page you have associated the app with function as the publisher of the app. The super admin must approve the association in the following 30 days. [Learn More](https://www.linkedin.com/help/linkedin/answer/a548360/).
+
+![LinkedIn Page Verification](./assets/linkedin/ln-verify-page.webp)
+
+Go to the *App Settings* panel and click on the *Verify* button. A modal will appear allowing you to generate a verification URL.
+
+![LinkedIn Page Verification URL](./assets/linkedin/ln-verify-page-url.webp)
+
+Generate the URL and send it to the page super admin. An email will be sent whenever the association has been approved or denied. Wait for the approval before proceeding further.
+
+## Request API Access
+
+For the Essentials LinkedIn Source use case, you must request the `Advertising API` product. To do so go to *App Products* panel of the app and follow below steps.
+
+![LinkedIn Advertising API Product](./assets/linkedin/ln-app-api-product.webp)
+
+::: warning
+Note that only one product can be requested per app. If you mistakenly requested a different one, you will need to create a new app from scratch.
+:::
+
+1. Click on the *Request access* button within the *Advertising API* product section.
+2. A modal will appear, fullfill the form as instructed and submit.
+
+![LinkedIn Advertising API Request](./assets/linkedin/ln-app-api-request.webp)
+
+3. Wait for approximately one minute, then refresh the page.
+4. A new button *Access Request Form* should appear in the product section. Click the button and complete legal details.
+
+::: warning
+Accurate and current company information is crucial. LinkedIn will carefully review your company details to verify their validity.
+:::
+
+5. When asked about the app primary use case, choose *Direct Advertiser*.
+
+![LinkedIn Advertising API Use Case](./assets/linkedin/ln-app-api-use-case.webp)
+
+6. When asked about what do you plan to do with the APIs, describe it without mentionining fetching or displaying data in your website. Focus on statistics or advertising, instead.
+
+![LinkedIn Advertising API Use Description](./assets/linkedin/ln-app-api-use-description.webp)
+
+## Generate a Token
+
+Once the app is ready you can generate a token with it and use it for authentication.
+
+![LinkedIn Token Generation Form](./assets/linkedin/ln-token-gen-form.webp)
+
+1. Visit the [LinkedIn Developer Portal Token Generator](https://www.linkedin.com/developers/tools/oauth/token-generator) tool.
+2. Select the app you'd like to generate a token for.
+3. Select the permission scopes. Usually that would be `r_basicprofile`, `r_organization_admin` and `r_organization_social`.
+4. Copy both *Refresh* and *Access* generated tokens.

src/essentials-for-yootheme-pro/sidebar.json

@@ -224,6 +224,10 @@
                 "text": "Custom Google Dev App",
                 "link": "/auths/custom-google-dev-app"
             },
+            {
+                "text": "Custom LinkedIn Dev App",
+                "link": "/auths/custom-linkedin-dev-app"
+            },
             {
                 "text": "Form Events",
                 "link": "/addons/forms/form-events"