Inputting compound rhythms

I am struggling to create a half note tied to a dotted quarter to fill a whole bar of 7/8. I can create a half note and a dotted quarter separately, but then can’t tie them together. What’s the best way to input notes that aren’t even numbers of beats?

enter first note, hit T, enter second note.

The method TylerE describes is how this works in note input. Outside of note input, you should be able to select both notes (or just the second one in fact), and press T or the tie button.