Servicing a leased vehicle

I am currently leasing a car, with the lease about to expire in c. half a year. The contract was renewed, so no service is included in the monthly premiums. Given that I want to return the car at the end of the lease contract, I would like to spend as little as possible on the upcoming service and oil change, which unfortunately I have to do a couple of months prior to lease expiration.

Is it obligatory to have the oil change/service at the garage where I hold my lease contract or is it ok to choose any local garage that could do it a bit cheaper? Will the lease company (one of the big ones) figure out that I had the car serviced by someone else and impose penalties when I return the car?

Is it mandatory for you to do it ?
Maybe just call the company and see what they say [can not speak from exp, never leased]

Check the contract. Last time I had a lease car I had to do all services at a garage of the choice of the leasing company.