A cheap amateur radio HF SWR meter is about £30, how much does your radio cost?
That SWR meter will probably give a reasonable result if it's a good quality SWR meter. HOWEVER, my experience with CB kit is, unless it's old CB kit, it's probably very poor quality & will not giving a good result, even where it's designed to work.
I have a very old Motorola 10 meter CB SWR meter that I was given by a friends family when he went SK & it's a lovely quality item that I have kept, as it really is a very good item. But I have also acquired several free cheaper & nastier meters via freecycle that have used for parts.
Edited to add my main SWR meter was a very cheap Avair amateur radio cross needle meter that I brought when I first got my foundation licence. I do have other meters, but my old Avair, is so easy to read that it's my favourite to use.