Is it ok to use the

androidx.compose.material3

package for a desktop app? Will it work?

Yes

Yes, it works fine for the most part. You won’t get dynamic colors like you will on Android, but the Material3 components will work work just the same as it would with the M2 components

I've just found this: https://blog.jetbrains.com/kotlin/2023/11/compose-multiplatform-1-5-10-release/#new-material-3-components-in-common-code - it looks like it's already integrated into the latest version. Isn't it? 😯

You should be able to implement it like

implementation(compose.material3)