Based on the level of respect or formality, you can say "How do you want to pay?" in Korean in 3 ways:

• Informal: eoddeoke naellae? (어떻게 낼래?)
• Formal: eoddeoke naellaeyo? (얼떻게 낼래요?)
• Very formal: eoddeoke naesigetsseumnikka? (어떻게 내시겠습니까?)