How to handle disconnections

As the title says, I want to know how the player would handle being disconnected/rejected from the server using blueprints

I couldn’t understand your question completely but I think Find Session node has a executable - On Failure that can resolve your issue.

I am using Dedicated Servers not sessions

PlayerControler has function End Play, Gamemode has OnLogout maybe it could help.

This doesn’t help, I am trying to detect if the player was kicked/banned so i can notify them of why they cannot connect to the server/got kicked from the server

maybe this link How do I disconnect from a Dedicated Server the right way? help you. is use
DISCONNECT in execute console command and it worked