You have the option to unlink a Steam/Facebook/Google/Apple account, if for example you want to link it to a different Ankama account.
Step 1: Log in to your Ankama account.
Step 2: Go to "linked accounts".
Please note: to unlink your account from Twitch, use this link: https://account.ankama.com/en/twitch
Step 3: Click on "Unlink my account".
Step 4: Confirm that you want to unlink your account.
Step 5: Enter the security code sent to your email address
Your Facebook/Steam/Google/Apple account is now unlinked from your Ankama account!