In Postmypost, go to the "Accounts" section and click "Connect".
In the window that opens with the list of social networks, click "Connect" next to TikTok.
A window will open for the official connection of the TikTok account to Postmypost, specifying what data and permissions Postmypost requires to operate. Make sure you agree with granting access and click "Connect".
After a successful connection, you will automatically return to Postmypost, where a list of available accounts for connection will open. Check the box next to the desired ones and click "Connect".