Coming from R
You can use DRModels.jl in two different ways.
If you already work in R with drmTMB, keep using its default R/TMB engine unless you have a specific reason to try Julia. It needs no Julia installation and is the established route for the full drmTMB workflow.
If you want to work directly in Julia, begin with the first model tutorial. The model ideas are the same: choose a response family, write a formula for the average response, and add a formula for variability only when that is part of your question.
Moving a familiar model to Julia
The R and Julia vocabulary page puts common drmTMB and DRModels.jl syntax side by side. It is the best next step when you already have an R model that you understand and want to translate it by hand.
The optional R bridge
drmTMB also has an optional engine = "julia" route for a limited set of models. It lets you keep writing an R formula while fitting the model with DRModels.jl. This is not required for either package, and it does not make every drmTMB model available in Julia. Follow drmTMB's Julia-engine setup guide only when the documented example matches your question.
For the current supported model types, use What is tested. For models involving spatial, temporal, or other specialised R workflows, stay with the documented native R route unless a Julia example explicitly says otherwise.
drmTMB articles without a DRModels.jl page
These drmTMB "Start here" articles have no DRModels.jl counterpart yet. Read them on the drmTMB site, and check any Julia-specific route against What is tested: