If you are a member of American Express Membership Rewards you can transfer your Membership Rewards points to your Singapore Airlines KrisFlyer account. Usually, 1000 American Express Membership Rewards points equals 1000 KrisFlyer Miles.
But through December 31, 2023 Amex is offering a 20% transfer bonus to KrisFlyer. Instead of the normal 1:1 transfer ratio, when you transfer 1,000 Amex points to KrisFlyer, you will end up with 1,200 miles. If you need KrisFlyer Miles, consider transferring before 12/31/23.