Unable to get apt-update and apt-upgrade to work on Bliss OS using Termux

Ideally, I am trying to gain root access to a Bliss OS (version 11.14) Virtualbox machine I have so that I can view saved PCAP files. Sadly, to get to the directory I have to be root. The only option seems to be installing a fake root module (https://www.crisisshelter.org/get-root-access-in-termux-without-root-fakeroot/) . However, this and several other things I have tried to do with Termux lead up to running apt-update and apt-upgrade. However, I keep seeming to get repository issues.

$ apt update && apt upgrade
Get:1 https://grimler.se/termux-packages-24  stable InRelease [16.8 kB]
Get:2 https://grimler.se/game-packages-24  games InRelease [9347 B]
Err:1 https://grimler.se/termux-packages-24  stable InRelease
  The following signatures couldn't be verified because the public key is not available: NO PUBKEY B0076E4908716168
Get:3 https://grimler.se/science-packages-24  science InRelease [9360 B]
Err:2 https://grimler.se/game-packages-24  games InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY BO076E4908716168
Err:3 https://grimler.se/science-packages-24  science InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B0076E490871616B
Reading package lists... Done
W: GPG error: https://grimler.se/termux-packages-24  stable InRelease: The following signatures couldn't be verified because the public key is not available: NO PUBKEY B0076E490871616B
E: The repository 'https://grimler.se/termux-packages-24  stable InRelease' is not signed.
N: Metadata integrity can't be verified, repository is disabled now. N: Possible cause: repository is under maintenance or down (wrong sources.list URL?).
W: GPG error: https://grimler.se/game-packages-24  games InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B0076E490B71616B
E: The repository 'https://grimler.se/game-packages-24  games InRelease' is not signed. N: Metadata integrity can't be verified, repository is disabled now.
N: Possible cause: repository is under maintenance or down (wrong sources.list URL?).
W: GPG error: https://grimler.se/science-packages-24  science InRelease: The following signatures couldn't be verified because the public key is not available: NO PUBKEY B0076E490B71616B
E: The repository 'https://grimler.se/science-packages-24  science InRelease' is not signed.
N: Metadata integrity can't be verified, repository is disabled now.
N: Possible cause: repository is under maintenance or down (wrong sources.list URL?).

I can't seem to find a fix for Termux anywhere online. Does anyone have a better solution to getting root access via Termux? UPDATE: I updated termux to a more modern version. However, I get "File has unexpected size" error when I try to run apt-get update, or when I try to install anything.

~ $ pkg install su
Checking availability of current mirror: ok
Get:1 https://packages . termux.dev/apt/termux-main stable InRelease [14.0 kB]
Get:2 https://packages . termux.dev/apt/termux-main stable/main x86_64 Packages [450 kB]
Ign:2 https://packages . termux.dev/apt/termux-main stable/main x86_64 Packages
Err:2 https://packages . termux.org/apt/termux-main stable/main x86_64 Packages
  File has unexpected size (451382 != 450311). Mirror sync in progress? [IP: 216.18.208.174 443]
Err:2 https://packages . termux.org/apt/termux-main stable/main x86_64 Packages
  File has unexpected size (451382 != 450311). Mirror sync in progress? [IP: 216.18.208.174 443]
Err:2 https://packages . termux.org/apt/termux-main stable/main x86_64 Packages
  File has unexpected size (451382 != 450311). Mirror sync in progress? [IP: 216.18.208.174 443]
Fetched 14.0 kB in 1s (10.7 kB/s)
Reading package lists... Done
E: Failed to fetch https://packages . termux.org/apt/termux-main/dists/stable/main/binary-x86_64/Packages File has unexpected size (451382 != 450311). Mirror sync in progress? [IP: 216.18.208.174 443]
E: Some index files failed to download. They have been ignored, or old ones used instead.

Does anyone know a fix for this?