A simple install resource for ArduinoJson 5 that enables you to run alongside ArduinoJson 6...
If you have Arduino Json installed it is likely version 6, and you have a sketch complaining about needing version 5, and you don't have eithe rthe skill or the inclination to pull it across.
However, there is a work around, while still having Arduino Json 6 installed.
All of this is from the Arduino Json v5 site. Any linking is for convenience purposes and no code changes are intended or made to the ArduinoJson-v5.xx.x.h file. The original source https://arduinojson.org/v5/doc/installation/ (i.e. you could achieve the same thing with a download and manual GUI folder placement)
To execute, from your terminal client of choice:
cd into you sketchbook libraries folder.
From there: $ git clone https://github.com/JHale716/ArduinoJson5.git ArduinoJson-v5.13.5
This will place the repo and the ArduinoJson-v5.13.5.h file for ArduinoJson5 into this folder.
In your sketch, substitute ArduinoJson.h for ArduinoJson-v5.13.5.h and you'll be good to go!
Simple and effective.