You'll want to use the ARM images instead of the default AMD64 images.
For Lemmy: image: dessalines/lemmy:0.17-linux-arm64
For Lemmy-UI: image: dessalines/lemmy-ui:0.17-linux-arm64
Those should get you pass any architecture related issues.
I've finally just got my instance up and running along with using my traefik gateway (instead of the nginx they have). It is 5AM on a Monday for me, so I better go take a quick nap before work. I'll make a separate post later on the steps I've taken to make that work "relatively cleanly".
Good luck!