Use #MiniSign to sign documents, archive the folder with signed documents and their signature files (*.minisig) in the usual way
Use #AgeEncryption to encrypt an file (eg: an archive), send the encrypted file (*.age) by any means to the recipient
#MiniSign
https://jedisct1.github.io/minisign
RWRK8XFYuCHjYX1J/7cKCUy6eQKNYVAurb/70Q6pK8kjGHALVORZGJ+o
#AgeEncryption
https://age-encryption.org
age1s3n5ehvm8h3xjkc985hzjznw9cv0lk9ezj5heyy4m7l654rkzslq07ylps
Alternatively use #GnuPG and email
#OpenPGP #FingerPrint #PublicKey
https://keys.openpgp.org/vks/v1/by-fingerprint/10761F0C272B3AAA52D4D9DB8806B58B124EA2A0