Oil from the exhaust tube

Hello everyone, this is my first time on this site and I find it quite interesting. I have a 2005 Nissan Primastar 100hp dCi, which is my go-to vehicle for everything, as I also use it for work. Over the years and with the mileage, problems have started to appear, and with the way things are these days, I can't afford to have it repaired at a garage.
That's why I need your help.
The most urgent problem is the oil leaking from the exhaust pipe. What do you think it could be?
Thanks.

It's probably the turbo.

Welcome to the forum, Josearatec. I'm not sure if you're referring to oil, oil burning smoke, or condensation (dripping).
If it's oil, the only thing I can think of is the turbocharger; the ceramic bearings might be worn. But that oil would burn and come out as smoke. Does this happen when the engine is cold? Is it consuming oil? If so, the only other cause I can think of is the turbocharger.

It looks like the turbo bearings; you'll probably have to spend some money...