Business Central 18.3 is just around the corner, and it comes with a long-awaited feature: support for OAuth client credentials flow, aka service-to-service authentication.
Many API integrations with Business Central SaaS are using the web service access key for basic authentication. But the 2022 release wave 1 (version 20) will remove this feature in favor of OAuth2. Since 2020 release wave 2 (version 17) a warning is displayed on the User card that the web service access key will be deprecated. This is only for SaaS and NOT for on-premise! For on-prem environments, the web service access key will still be an option.