Currently, form links will only populate on existing records. They won't appear on a blank form.
To add a link to your form:
Navigate to your source table. In this example we will use the "Product Content Backlog" table (Image 1) for our "Product Content Requests" form.
Add a new column to your table using the following parameters (Image 2):
Data Type: Text
Default Value: You can set this to your link if you want a single URL to populate as the default. This value can always be updated in the table.
Max Length: 500
Allow Linking: Yes
Add in your URL to your relevant row/record.
Add this column to your form by navigating to the Form Fields table and inputting your new column as a row (Image 3).
Under Data Format Type, select LinkURL.
When you navigate to the form record linked to your row in step 3, you will see the URL populated as below (Image 4):