Manchester United won't be able to qualify, even though the possibility is small, they are not really ready to be in the UCL this season, they still have a lot to improve in their squad because in my opinion they should focus more on the EPL and improve their position so they don't get worse. in the domestic league, they can still have the opportunity to get another UCL ticket next season.
I don't think is possible for Manchester United to qualify from there group because there point is quite low from other team but if they had improved on there performance earlier they would have win themselves to the third position on there table.
However there group match against Bayern Munich is quite impossible for them to win the match because Bayern Munich is very good on this season and they have won almost all there matches this season, but however even if Manchester United wins them there is still know chance of Manchester United to qualify because Galatasaray and Copenhagen will never play draw and any side that wins become the second position on the group.
Manchester United should forget about qualifying for the last 16 of the Uefa Champions League and focus on their Premier League matches because they have a big test to beat Bayern Munich on match day 6, which will be difficult for them to achieve. Onana will be another reason why Manchester United can not defeat Bayern Munich because of his errors.