Plenty of 20v power banks.
Your main issue would be getting the correct DC jack if it’s an unusual type. If it’s a normal DC barrel jack, get the correct size and make sure polarity is also correct.
Yes, unfortunately the problem is in the connector, my laptop doesn't have a Type-C connector, I have a round charging connector. I have not yet found a cable that can connect the power bank and my computer.
This page, which can also be found at the website of the link provided by @Harald Kapp in his post #2 above, offers a power bank with several barrel connectors. You might want to visit the website of this vendor to find out if what they offer will work for you.
Thanks Hop @hevans1944 ,
I wasn’t aware that @Harald Kapp inserted a link. You either for that matter. I can’t see links on my phone, the text is black or extremely dark blue. I never had this problem before the site changed.