Set the launch options in Steam Run the launcher, allow the game to update and perform a first run which will fail.

Run protontricks 205710 d3dx9 d3dx9_43 corefonts

Edit your eqclient.ini in /steamapps/common/Everquest F2P and set the line VertexShaders=TRUE to VertexShaders=FALSE

This works even since the 64bit client update Feb 15 2022