1. Click on the Launch menu from the left-hand sidebar.
2. Click on the + Load Media button to open your media library.
3. Select the creatives you want to launch by checking the boxes next to them, then click "Select [x] creatives" to proceed.
4. Once the creatives are loaded, you can add the required fields such as primary text, headlines. Scroll to the right to locate the "Lead Gen Form" column.
5. Use the dropdown menu to select the instant form you’ve set up in Ads Manager, and choose your preferred form for the ad.
Lead forms are not supported for Flexible ad formats
6. Click "Launch Ads" to launch the ads.
Troubleshoot
If no lead forms appear in the dropdown, click "Reconnect" at the top to reauthorize your Facebook account and grant the necessary permissions for the connected Page — this will sync your lead forms.