There's a lot of documentation to be found on integrations with REST
https://docs.mendix.com/howto/integration/consume-a-rest-service

and with SOAP
https://docs.mendix.com/refguide/consumed-web-services

Good luck.

https://www.mendix.com/blog/flexible-integration-options-to-support-next-generation-low-code-applications/

and

https://docs.mendix.com/howto/integration/publish-rest-service