I have always used 2-part glue that is available from many boating supplies stores. I have read where the additive part only provides better protection against gasoline and is not needed for the glue to work properly. So maybe the 1-part glues are adequate.
Search this SBO board and I think you will find specific recommendations for your dinghy. The one warning that I think is common to all of the glues is that they be used under low humidity conditions. And the area to be patched is clean and roughed up. If the dinghy had been cleaned or "protected' with a silicone based product, just wipe with the approved solvent in one direction and don't use sandpaper to rough up the surface. This is because the sandpaper can actually cause the silicon to become embedded in the surface and ruin an otherwise perfect adhesion.
If you do an internet search on "best glue for pvc inflatable dinghy repairs" you will find lots of information.