More than happy doing soldering. Got practice making an 8 x 8 x 8 LED cube. LolYou're missing the step that would make this device suitable to be connected to a mains plug, in the first place!
View attachment 288485
Having said that, and having a look at Clive's video; if the OP is confident with soldering, they could solder on some 2 core 0.5mm2 mains flex (directly to the PCB) and add some strain relief.
I just wanted a reliable digital led thermometer. They will be used on a fridge bed (for fish) and two lobster holding tanks in a restaurant .And thats what would worry me.
If the designer hasn't taken the time to make sure that device fails safe (ie. failure = output OFF) then what other safety features has he omitted???
The output won't be used at all.