Engine warning light and OBD messages

[Galagemm]

Berlingo Flair petrol 2019 (new to me in March!) 

My engine warning light came on yesterday just after filling up. 

I drove home and today my dad plugged in an OBD and got the message in photo


P2176 Throttle Actuator Control

System Idle Position Not Learned

Any ideas of this will be expensive? And if covered by my extra warranty? (Warranty is from dealer as out of 5 year Citroen warranty)