Hello!
Thanks for another great question! The “Contact blocks” in the footer cannot contain links in the current version of the BoldGrid Theme Framework, but that’s a great idea for a feature request.
There is another way to accomplish this though, which will be even easier since you already have your phone number in a navigation menu from your previous question.
While you’re in the Customize menu, scroll down to your footer and click the Edit (Pencil) icon. The “Contact Blocks” here are only plain text, so remove the block that has your phone number.
Next, click on Edit Footer Widgets and then Add Widget -> Navigation Menu. Select the menu you’re using for your header menu, and you’ll have a clickable link just like the one in your header. Here’s a short video of the process:
I hope this helps!