Got it to work! It is similar to how you would do it on a PC, but due to having less settings it has a few extra steps.
1. Make a virtual sd card(1gb was enough) sd.raw. I used winimage I believe.
2. Put it in the dolphin-emu/Wii folder
3 Put the boot.elf for a launcher like minima or gecko in the same folder.
4. Here is where it gets different since I could not find insert SD card or set as default iso in settings
5. You need to edit the dolphin.ini in dolphin-emu/config. Use a text editor to do this. I used jota text editor from the play store.
6. Change "WiiSDCard= False to True. Remember the space after equal sign.
7. Change DefaultISO to the path where your brawl iso is.
8. Load the boot.elf in dolphin.
It seems to crash more often than vbrawl for me and has some graphical glitches and screen flickering than vbrawl, but it does work at least. I'm using a oneplus5 to load dolphin, am getting a good 50-60 fps unless there some larger attacks happening like final smashes, but is not entirely smooth. Maybe locking it at around 50 may be a better idea?