Try this first
Have it sent again
Open lonelyduck.io/saferow/activate and press Email my license, or use Find my license on this page. It goes to the address you bought with. In Saferow, Settings › License › Email me my license does the same. Open the email on your Mac and press Activate Saferow on this Mac; Saferow asks before it activates anything. Or paste the license (it starts saferow-license-v2), or the whole email, in Settings › License. Signed in at lonelyduck.io with that address, Account › Saferow has Copy license and Resend email.