Check for paramters that has url
Append Burp collaborator link in the host header
Test for SSRF on functions that accept external resources
Use this cheatsheet for potentials ssrf :
https://cheatsheetseries.owasp.org/assets/Server_Side_Request_Forgery_Prevention_Cheat_Sheet_SSRF_Bible.pdf
Add img tag or iframe tag pointing to your domain when html is allowed
Test for function that allow external images
Add %0a as bypass or %00
Test SSRF on svg uploads
Test in webhooks