Update Custom Domain used in prefill form field URL

Update Custom Domain used in prefill form field URL

HI - I have added a custom domain for my forms. For each form, I have went to general settings and made the forms use the custom domain. However, on the 'share' tab, I cannot seem to change the prefill form field URL to be my custom domain. The only domain available is your public domain of  https://forms.zohopublic.com/xxxxxxxxx . Can I just substitute my custom domain URL and insert field alias's as normal and it will work? Thanks!