There are a few things that changed between Dolibarr 3.1 and 3.2 about the management of templates, so you should compare a standard template from D31 with the same template in D32 to see the changes.
More specifically for propales, you should replace all
propale->
into
propal->
because the object changed. Also the mkdir function was changed into something like dol_exdir or something akin.
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