Welcome to Android Central! There are two possible ways. The first is Adoptable Storage, where the SD card is formatted as Internal Storage (not Portable Storage). Not all devices support this. When you insert an SD card, if you don't get the option to format as Internal Storage, then the phone doesn't support it.
The second way is the "Move to SD" option in Settings>Apps when you look at a specific app's info. This is generally for older phones (although it's still an option on some recent Samsung phones). This only moves a portion of an app to the SD card (mostly data).
We generally recommend against either of these options. Relying on an SD card as part of Internal Storage increases the risk of system crashes and data loss, because SD cards are inherently less reliable than onboard memory, and if/when the card crashes, a lot of problems can occur. In addition, performance of the apps generally takes a hit, since read/write speeds on SD cards are significantly slower than onboard memory.