After you create your Lnk.Bio account copy & paste your Lnk.Bio URL in your Instagram Profile, under the Website field of your Instagram biography.
Step 1
Head over to your Lnks page, and tap on the Copy button located at the top-right of your page, as shown below:

Step 2
After you copied the link, head over to your Instagram account, click on Edit Profile and add the link in the Website field as shown below
