Hello
You wont go too far wrong with every 8-10000 kms and any 5w40 fully synthetic or even 10w40 semi sythetic, depending on what you can get there.
tbh if oil changes even enter your thought process, you're doing better than a large % of other owners. I wouldn't worry too much about official oils on a 5 year old panda unless the opportunity presents itself.
What will be important this year for you if you havent done it yet, is to change your coolant for a good Red Oat one as the max life of that is 5 years, at a push.