i don't understand how this can be an argument regarding the 5th amendment right against self incrimination if it doesn't address schmerber vs California (https

i don't understand how this can be an argument regarding the 5th amendment right against self incrimination if it doesn't address schmerber vs California (https://supreme.justia.com/cases/federal/us/384/757/ https://supreme.justia.com/cases/federal/us/384/757/) which found "Since the blood test evidence, although an incriminating product of compulsion, was neither petitioner's testimony nor evidence relating to some communicative act or writing by the petitioner, it was not inadmissible on privilege grounds." I'm not an expert, but I'd note that Fisher Vs. United States which gets brought up several times was about the accused individual's lawyer producing documents the individual had given them. And a large part of the judgment in the case is the difference between ownership and possession (as seen in the decision of couch vs. united states which it relies on). In any case fisher said that you couldn't be compelled to testify to affirm the truth of the contents of the documents sought and that the password would decrypt them. But decrypting files is affirming a truth in the documents sought, as the government lacked testimony of their encrypted existence on that hard drive and of the passwords ability to unlock them.