def sign_payload(payload):
    payload_bytes = payload.encode()
    signing_key = load_signature_key()
    signed_b64 = signing_key.sign(payload_bytes, encoder=Base64Encoder)
    return signed_b64.decode()
def sign_payload(payload):
    payload_bytes = payload.encode()
    signing_key = load_signature_key()
    signed_b64 = signing_key.sign(payload_bytes, encoder=Base64Encoder)
    return signed_b64.decode()