When offline, those services are not available, so you will need to download the country data in Maps Pro to be able to search for an address.
Check out this page to learn how to download maps for offline use: How do I download maps for offline use?
Once you have downloaded a country, the search box will be different. Note that if you have an internet connection but want to use the downloaded data instead of online services, go to Help > Options and select "Downloaded Data" as a data provider.
For instance, here is what the search box looks like after you have downloaded a few regions:
Start typing a city name to get suggestions:
Note: by default, only large cities will be suggested to you. If you are looking for a smaller city, use the "Villages" toggle button. If you only want to search by postcode, use the "Postcodes" toggle button and start typing the postcode you are looking for.
Select a city in the list. Click "OK" to center the map or this city and start typing a street name:
Once you selected a street, click "OK" to center the map on this street or choose an entry in the "Building or Intersection" list. Depending on the amount of data in this area, some building numbers might not be available. Click OK to center the map on your target: