UserName123 Grab also refused to start for me too (no white screen, just instant crash) on my Pixel 6. I resolved it in a related way, by using a fake GPS location to have it appear that I'm in Indonesia so I could set up my Grab account and addresses prior to traveling there.
Another option would be to look at Gojek, an alternative app with similar features and another large user base, which runs fine from out of country and you just have to pick the country you're "in" from a list. FWIW I found it very fiddly to use, and I think Grab is a nicer app.
If anyone is looking how to set up a fake GPS location, which you can switch on or off as needed, and have several locations saved, first you need to enable developer options, which is very easy to do:
For Pixels, go to Settings > About Phone > Build number, and keep clicking on the build # until you're told Developer options are enabled. (7 times if I remember right.) You'll then have a new Developer Options page in your Settings.
You need to have a Fake GPS app installed. I've used this one for years:
https://play.google.com/store/apps/details?id=com.lexa.fakegps
Once installed, go to your Developer Options page and search for location, and change the setting to use this app as your fake GPS location app.
From then on you can use the app to set some favorite locations and turn the fake locations on or off.