fix: render button for registration link

[amandazhuyilan]

Description

AAI-832: Render the templated button for registeration link in the incorrect email

Changes

• Render the templated button for registeration link in the incorrect email

Checklist

• I have commented my code, particularly in hard-to-understand areas
• I have added unit / integration tests that prove my fix is effective or that my feature works
• I have run all tests locally and they pass
• I have updated the documentation (if applicable)
• For any new secrets, I have updated the shared spreadsheet and the GitHub Secrets.

How to Test Manually (if necessary)

[marius-mather]

good to go