I'm going to add my way of doing the link & 'dast' anyone to laugh at it. Well. Y'all can laugh if you want to--I'll even guffaw witcha.
Here's my way of linking a gallery piece to a post... (take note Lickey/UtahAnn)
Once I have my piece in our gallery, it has a url I can read.
When I want to link it to a post, I click on the hyperlink icon & type in the address. (No I don't do copy & paste! I'm old & a curmudgeon so don't try to teach me how to suck eggs!)
When I have the url done I click on 'ok'. That puts the link in my post, but does it twice. So I backspace from the end of the visible url 'til I reach the end of the first one. Then I just put in the name/word I want. When I did this on 2Ps, the OK click would give me a chance to do the 'name'. This program doesn't seem to, but it's a minor issue for me. Just a few more keystrokes.