[BUG FIX - API] Add missing api province route.

| Q	                       | A     |
|--------------------------|------ |
| Bug Fix?        	| y     |
| New Feature?	| n     |
| BC Breaks?	       | n     |
| Deprecations?	| n     |
| Tests Pass?	       | n     |
| Fixed Tickets	       |        |
| License	               | MIT |
| Doc PR                  |        |

- add `exclusion` condition to `relations` prevent  error "get  method of none object" (Province is nullable).