I don't see a RT pin in the datasheet :
https://www.ti.com/lit/ds/symlink/lm64460-q1.pdfAs for MODE / SYNC , see pages 17 and 18.
But I really have to wonder why you'd decide to make a 5v 0.7A dc-dc converter with a chip that costs 5$ in small quantities. It's a chip designed for up to 36v, with up to 6A switching current, not for circuits which are meant to output less than 1A of current.
You have much better cheaper regulators for 1-2A of current, they may be slightly less efficient at maybe 92-95% instead of 97% but they'll cost under 1$
A cheap 30 cents AP62250 will do up to 18v in, up to 7v out, 2.5A out ... with around 90% efficiency :
https://www.digikey.com/en/products/detail/diodes-incorporated/AP62250WU-7/12349212The datasheet contains everything you need, example schematic, recommended values, even how to layout the circuit.
Richtek RT6224D is up to 18v, up to 5v out, up to 3A, and will go up to around 95% efficiency :
https://www.digikey.com/en/products/detail/richtek-usa-inc/RT6224DHGJ6F/6205448 (note theres also a RT6224 but that one runs at lower switching frequency)
MP1477 is another good example :
https://www.digikey.com/en/products/detail/monolithic-power-systems-inc/MP1477GTF-Z/7361360