Does the 2019 Nissan Frontier have a timing belt or chain?

Though some generation Nissan Frontiers have a timing chain, Yours is going to make use of a timing belt, and these do need to be replaced somewhat regularly throughout the life of the vehicle. When the belt's replaced, it often makes sense to also replace the tensioner, water pump, any of the other drive belts and hoses, cam seals and crank seals. That'll cover You for another 60k or so miles, at the least. All that work should also be able to be completed by Your Nissan dealer for around $700-$800, which includes both labor and parts to do the job.