can I have a download link to update locally last version of bv6800, via OTA say no update, tech service tell me one update is available

I bouth on presale the 6800 pro after beign very satisfied for years with 6000. Unluckily, this 6800 has too much mic problem. I contacted blackview directly and they say "find someone to fix in Italy" "we may pay the repair if is not expensive". Very disappointing. I understand ...

My 6800 say always no update available. can you tell me where to download, I will apply manually inmediately.

I was very happy 6000 user, but the 6800 I bought in presale has too much mic problems. They told me this can solve.