How to execute scripts with a plugin without using loadstring()

You can’t anymore. Anything that executes scripts will automatically be banned, including methods that don’t involve loadstring. The only way is to upload it, wait for it to be deleted, appeal it and say something like “this asset does not run anything malicious and uses roblox features as intended” then wait and hope for the best. Note that you will have to go through this appeal thing every time you update the plugin.