Followed instructions but remote won’t work

MyXr15 remote stopped working even after I changed batteries. I followed all instructions from live chat with xfinity and the issue is not resolved. The problem was that the instructions required pairing the remote with the tv and, because I am stuck on HMDI 1 ( roku), I can’t access the steps that should appear on the tv screen. I tried to disconnect HDMI1.  When only HDMI2 is connected I see a message of “ no signal check input”. I don’t have the original tv remote and cannot change input manually on my tv.  I see the box green dot when I press buttons on the remote, but voice command to pair, pushing  both the xfinity button and the I button does not change anything on the screen. The technician says I need a new remote. I got the xfinity remote app but it doesn’t have an input change button. Is there something else I can do?