I think there has been a Field Service component once for Dynamics AX. Not sure if it's still "living" and whether it was from an ISV or from MS directly.
If you want to go with the probably more recent "Microsoft Dynamics 365 Field Service" you have to use a different plattform than for Dynamics 365 Finance and Operations. Dynamics 365 Finance and Operations is based on former AX plattform whereas "Dynamics 365 Field Service" is based on former Dynamics CRM plattform.
There are several ways to integrate these both plattforms with each other however you might not come around having some integration efforts to create an interface.
You could check for example this:
docs.microsoft.com/.../dynamics-365-integration
There are also some interface tools like Scribe or LogicApps...