Help with Multiscrape Code

Hey guys, i got this new smart water filter that has a dashboard page with the incoming and outgoing data of tds values i wanna grab. im awful with scraping can someone help out? Here is the site. https://watertds.com/. and here is my code so far: I believe there is a login element on the site that i use google for. not sure how that all works. currently there is no api for this stuff so scraping is the only option.
multiscrape: