Open Facebook and log in to your account
Go to the Facebook page you want to find the link for
Click the page name to open the page
Look at the address bar in your browser
Copy the full URL from the address bar
On the Facebook app, tap the page name
Tap the three dots on the page
Select Copy link or Share link if available
Paste the copied link where you need it
If you manage the page, go to Page settings and check the page username or page URL
Use the page username in the link format facebook.com/username if needed