For calling services on moqui you can use remote procedures. your best bet is to call them through http with a rest api.
At "/apps/tools/dashboard" you can see the swagger apoi docs of different methods under the "REST API: Swagger UI" section
An example can be found when trying the moqui tools rest api at that section.
GET - "/rest/s1/moqui/basic/enums" will return a json with a list of the enums.
If you want to use a custom service, You need to declare an attribute in your custom services to allow remote access and can send http requests to it.
For calling services on moqui you can use remote procedures. your best bet is to call them through http with a rest api.
At "/apps/tools/dashboard" you can see the swagger apoi docs of different methods under the "REST API: Swagger UI" section
An example can be found when trying the moqui tools rest api at that section. GET - "/rest/s1/moqui/basic/enums" will return a json with a list of the enums.
If you want to use a custom service, You need to declare an attribute in your custom services to allow remote access and can send http requests to it.
Some extra information can be found at: https://www.moqui.org/m/docs/framework/System+Interfaces/Web+Service
If you run into authorization problems with the rest api, that's solved in this question: moqui:In moqui how to access rest without sign any user