Attempting to send a simple txt file (soon to be csv files) from Windows Server 2019 using scp command (or sftp, or ssh) to a remote server. Remote server employee gave us a username and password to login with. WinSCP works fine. Our security team would like us to not use WinSCP, but to automate it using ssh (which currently they are trying to find a way with scp).

Initial command (port redacted):

scp -v -P ***** Test.txt username@remoteserveraddress:/

Output here:
exec request failed on channel 0

C:\Users\username>scp -v -P ***** Test.txt username@remoteserveraddress:/
Executing: program ssh.exe host remoteserveraddress, user username, command scp -v -t /
OpenSSH_for_Windows_7.7p1, LibreSSL 2.6.5
debug1: Reading configuration data C:\\Users\\username/.ssh/config
debug1: Connecting to remoteserveraddress [remoteserveraddress] port *****.
debug1: Connection established.
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\username/.ssh/id_rsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\username/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\username/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\username/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\username/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\username/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\username/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\username/.ssh/id_ed25519-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\username/.ssh/id_xmss type -1
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\username/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_for_Windows_7.7
debug1: Remote protocol version 2.0, remote software version Serv-U_15.3.1.155
debug1: no match: Serv-U_15.3.1.155
debug1: Authenticating to remoteserveraddress:***** as 'username'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: ecdh-sha2-nistp256
debug1: kex: host key algorithm: ssh-rsa
debug1: kex: server->client cipher: aes128-ctr MAC: hmac-sha2-256 compression: none
debug1: kex: client->server cipher: aes128-ctr MAC: hmac-sha2-256 compression: none
debug1: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ssh-rsa SHA256:superSECRETKEyRedactedForMyProtection:)
debug1: Host '[remoteserveraddress]:*****' is known and matches the RSA host key.
debug1: Found key in C:\\Users\\username/.ssh/known_hosts:1
debug1: rekey after 4******6 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: rekey after 4*******6 blocks
debug1: pubkey_prepare: ssh_get_authentication_socket: No such file or directory
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: password
debug1: Next authentication method: password
debug1: read_passphrase: can't open /dev/tty: No such file or directory
username@remoteserveraddress's password:
debug1: Authentication succeeded (password).
Authenticated to remoteserveraddress ([remoteserveraddress]:*****).
debug1: channel 0: new [client-session]
debug1: Entering interactive session.
debug1: pledge: network
debug1: Sending environment.
debug1: Sending command: scp -v -t /
exec request failed on channel 0
lost connection