Giant uses the same frame dimensions across their bikes, I have a giant roam 3, it's similar except for the fork suspension. I use this one specifically https://www.amazon.com/dp/B06XCR516P/ref=cm_sw_r_cp_apa_fab_hPmEFbBJ8AF2Z
I like it because it's wide enough when you need to lock it to something that isn't a bike rack. Can fit the rear wheel, frame and object you're locking to well.
Thanks ! How does this look? Kryptonite Kryptolok 12.7mm U-Lock with FlexFrame-U Bracket https://www.amazon.com/dp/B06XCR516P/ref=cm_sw_r_cp_api_glt_fabc_68J1PGXAR7GZNDAKT8D8?_encoding=UTF8&psc=1