Click and holding a link doesn't always allow opening it in my app.

I have set up Firebase Dynamic Links, which allows users to click a link in their email which takes them to my app (and logs them in).

On my iPhone running 14.4 this is working fine, I can click and hold the link and the option 'Open in <My_App>' pops up.

However on my iPad running 14.4, when i click and hold the link in my email, the option 'Open in <My_App>' does not appear.

How do I get it to appear? It just opens up in Safari but on my iPhone it allows me to open it in my app.
Click and holding a link doesn't always allow opening it in my app.
 
 
Q