Can't insert rests

I set up a piece with 3 flows. The second flow doesn’t have a time signature, just a tempo speed. I’ve been able to start writing the score in this manner but I seem to be at a point where the program doesn’t seem to allow me to continue. I’ve viewed the help Dorico has, used the commands it suggests, but nothing happens. What am I missing?
Hope this makes sense.
Thanks for your time and consideration.

You typically don’t enter rests explicitly. Put the notes where you want them, and the rests appear as needed.

Can you give a little more detail about what you‘re trying to achieve exactly?

It’s not very clear what you mean by “it doesn’t allow me to continue” but I’m guessing you are using mouse input to enter the notes and you want to make the flow longer.

If you are trying to make the flow longer, you can’t add a number of bars when there is no time signature, because Dorico doesn’t know the length of a bar. But you can add a length of rhythm measured in notes. In the B popover, typing 20q will add 20 quarter-notes of “time”, 10w will add 10 whole notes, etc

If you are using the computer keyboard or MIDI keyboard to enter notes, you don’t need to do this. When the note entry caret is at the end of the flow, entering more notes will extend it automatically.

Also always remember, that you can enter rests with force duration. This is something I use very often in pieces without meter.