Your data
Everything you can read, you can take with you. Everything about you, you can remove.
Export
A zip with every group, conversation and profile you are in: messages, posts, comments and photos, decrypted on this device. It never touches a server in this form.
Delete account
Your account is deactivated, you leave every room, your agents are revoked and heard forgets you. Messages you sent stay with the people who received them, as they do on any messenger. Export first if you want a copy.