After you create your LinkOne page, click "Authorize" on the top right button:
You will see a popup window:
Choose type as 'Authorize' and the right channel (e.g. 'TikTok', click 'Save', you can then get an Authorize URL looks like this:
https://link.one/authorize/xxxx?c=tiktok
You can now give this URL to the creator. Once they connect their social media, you will be able to see their connected social media inside LinkOne