Multivariate time series forecasting with trend and seasonality

I’m working on a dataset which has city and product level sales for the past 3 years – on a daily level. My objective is to forecast the sales for the next 3 months – for a given city, product and date.

Now, I also have other features in my dataset which will impact my forecast, such as discount, days since launch, product_sales_decile, etc. In addition, I also see seasonality and trend being a factor for my forecast.

I have very limited experience with multivariate time series forecasting and wanted to know are there any good models which help in the same? The most viable one I came across is VAR and VARMAX, but it is mentioned that it is best suited for data without trend and seasonal components.

Any help/guidance is appreciated.

PS Any tips on how to efficiently do this forecast for over a 1000 products across various cities?