kossai | how to install thing that do not want to install

swear-y frustrate ahead , need of some tech help , linux .

freetube . captions broken for quite some time now because of update youtube push . developers fix pretty quickly , but not put out full release yet - this is only available in nightly builds . no fucking idea how to navigate github , no fucking idea how to get nightly build , so just grit teeth and hope would get release soon . but too long now , really sick of wait , so check in again . someone finally give instruction how to get nightly build . great , so have to actually make account for this ! make bullshit throwaway account , follow steps , get deb installer file .
crack open deb installer file , and get error : already at latest version . install button is non functional .

question 1 : why ?
question 2 : how to fucking fix ?

need captions to work . and while can still open in youtube nocookie player to get captions , really just want to use freetube as freetube fucking intend to use , because youtube nocookie player is absolute garbage bullshit !