This is an important title for God that shows the relationship between God and Jesus. (See: [[rc://en/ta/man/translate/guidelines-sonofgodprinciples]])
Jesus speaks of the work that he must do, including dying on the cross, as if it were a bitter liquid that God has commanded him to drink from a cup. The word "cup" is an important word in the New Testament, so try to use an equivalent for that in your translation. (See: [[rc://en/ta/man/jit/figs-metaphor]])
Here "cup" is a metonym that stands for the cup and the contents within it. The contents in the cup are a metaphor for the suffering that Jesus will have to endure. Jesus is asking the Father if it is possible for him not to have to experience the death and suffering that Jesus knows will soon happen. (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-metaphor]])
This can be expressed as a full sentence. Alternate translation: "But do not do what I want; instead, do what you want" (See: [[rc://en/ta/man/jit/figs-ellipsis]])