There are four ways you could wind up holding some of a stablecoin: You could create a trustline indicating that you are willing to hold the stablecoin and then someone could pay it to you. You could create a trustline indicating that you are willing to hold the stablecoin and then make a payment to yourself denominated in the same currency as the stablecoin. You could place an offer to acquire the stablecoin and then someone could take that offer. You do not need to create a trustline in this case. You could lock up some XRP and issue the stablecoin. You do not need to