Redshift can sometimes be unstable in Blender, this has nothing to do with the addon. We suggest saving your file once you've converted your material(s), before switching to Redshift IPR mode.

Select the Cycles/Eevee material that you'd like to convert in the Material Properties panel and hit the big Convert Material button. Done!

The addon is located under the Material Properties panel

The addon can be installed in the usual way:

Go to Edit > Preferences > Add-ons > Install

find the addon .zip file where you saved it and click Install Add-on

The addon should automatically detect your PBR textures based on their name. However to ensure a successful conversion, make sure your texture nodes or maps include their respective map type in the name. For example - to detect a roughness map, the texture on disk or the texture node in the Cycles material should have the word "roughness" in its name.

Please also note that the addon will not convert ALL Eevee or Cycles based materials. It is currently only intended for PBR map based materials using linked texture maps. Other types of materials and a wider range of map types will be added in future.

Displacement needs to be enabled under the Redshift options in the Object Properties panel before the displacement set up in your material has any effect.

The addon is currently compatible with Redshift version 4.1.0 and Blender 4.2.0

Unfortunately there is no method of sharing editable Redshift materials between 3d Software's. However it is possible to export Redshift materials in Blender as Redshift proxies (.rs files). Those will work in any 3d Software where you have Redshift installed. However the materials won't be editable. This is how .rs files are designed and applies regardless of the 3d Software used to create them.

For an overview of Redshift proxies in Blender, you can watch this video:
https://www.youtube.com/watch?v=dS-aqMOYZ-4 

If you use the "Add Principled Setup" function of the Node Wrangler addon that comes with Blender. It will automatically create a Cycles material from your PBR texture maps.

You will then be able to convert this material with Cycles to Redshift PBR Material Converter.

You can do the above by adding a new Cycles principled node and with the node still selected, clicking "Add Principled Setup". You can then navigate to the maps and select the ones you want to use.

Please read the Node Wrangler documentation for more information:
https://docs.blender.org/manual/en/latest/addons/node/node_wrangler.html#add-principled-texture-setup