Step 1: Go to https://business.facebook.com and login with your credentials
Step 2: Click on the Business Manager Tab followed by Business Settings.
Step 3: Under Business Settings click on People and assets > Page > Assign Partner
Step 4: Paste the Onlinesales.ai ID in edit box
Onlinesales.ai – 1693180044319778
Step 5: Click on confirm to verify that Onlinesales.ai is added successfully.