You can't. Both LG and Samsung realized that using an SD card as internal storage was one of the bad.ideas.of.the.millennium, so they didn't implement it. Using an SD card as internal storage eats the card in a relatively short time. (SD cards should last for decades, at least. [I have a few with the astounding amount of size of
32MB - and they still work. Useless these days, but they still work. 1/30th of a GB.] Using an SD card for internal storage can kill it in months. Then you have a problem. You don't have the apps that were installed on it - but the system says they're installed, so you can't install them. And, since they're no longer there, you can't uninstall them. So you have to back up
everything, do a factory reset, set your phone up again as if it was new, then restore everything in your backup. Until the next time you crash an internal SD card. [The same thing happens if you move an app to a card formatted as portable, or external, storage. If the card goes [and it goes quickly, for the same reasons that one set as internal storage does], you're back to a factory reset.)
So all-in-all, putting apps on SD card, internal or external, is bad. Put data files (documents, pictures, music, etc.) on SD cards and apps in internal eMMC storage. If you don't have enough internal storage ... that's why people keep buying new phones. Apps keep getting larger, Android keeps getting larger, old phones don't. 32GB should be enough space for all the apps you use all the time. Keep apks of the ones you don't use all the time (
Apk Extractor will create an apk of any app) on the SD card. If you need that app, tap it and it will install. Use it, then uninstall it. No reason to keep an app you use once a month in the phone's storage permanently.