Would "Jag måste få plånboken" work well enough here or do you need "hämta"?
My guess is that it probably doesn't as it seems that "få" is a passive interpretation of "get" i.e. someone needs to actively give it to you, and "hämte" is a more active interpretation i.e. the subject must actively retrieve it, correct?
I'm just curious, why is this not 'Jag måste hämta MINA plånboken' if it translates to "I have to get my wallet". The reason why I am still curious even after reading the comment that was posted above, is because there were a few other similar translations where I believed that 'My' was implied but I was marked wrong because those sentences did not contain 'min/mina/mitt'.