Some additional helpful references. Afaik Basic Auth has not been publically depricated yet, but NTLM has. OAuth for External Applications for On-Prem is available as of 2021.4
https://docs.uipath.com/orchestrator/reference/authenticating
Anil_G
ashokkarale
jinal.shah
Gautham_Pattabiraman
postwick
chandreshsinh.jadeja
vrdabberu
Ajay_Mishra
sven.wullum1
Vyshnavi_Nalumachu