apt-get update prevented by signature failure

I am trying to apt update on my WSL sudo apt-get update but getting this error.

Err:6 https://linux.qmk.fm  focal InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8B748CC185DF5DA1

I tried out the below command as this post suggests and tried different urls for --keyserver gpg --recv-keys --keyserver hkp://pgp.mit.edu 8B748CC185DF5DA1 and looked up openpgp https://keys.openpgp.org/search?q=8B748CC185DF5DA1 but no luck there. Is this something you can help me with please? Should I raise this as a qmk_firmware issue?