you use his oracle to build out a DLC of your choice..
Here is a video going over the s-wallet and the creation of DLCs.
Here is a list of all the oracles that have published
Here and here is a list of already created DLCs, that you can copy or edit to fit your bet.
Fiatjaf going crazy with DLCs lately. Wish there was an easy to way to bet over lightning (or I knew how already, heh)
For those interested: https://oracle.suredbits.com/
and this particular DLC is: https://oracle.suredbits.com/announcement/4ff9d00aae9be60e503355862dca8fec9e29410c73cbf4bec59858ae2f198859