to
Creates a URI string bitcoin:address optimized to be encoded in QR codes.
If the address is bech32, both the schema and the address become uppercase. If the address is base58, the schema is lowercase and the address is left mixed case.
Quoting BIP 173 "inside QR codes uppercase SHOULD be used, as those permit the use of alphanumeric mode, which is 45% more compact than the normal byte mode."