If you want to link your YouTube Channel on TikTok account, you can follow the next steps:-
#1). Tap on the person icon at the lower right of your screen to open your profile. – You may need to log in to view your profile.
#2). Go to your profile page and tap “Edit Profile”
#3). Tap on “Add your YouTube”
Choose your YouTube account and click on allow. Now it’s done.
In the same page, you can also edit your username, nickname, Instagram ID, YouTube channel and profile description.