If you are using Shopify plus store then only it's possible to make the further changes on the checkout page.
Kindly refer the above link for making the further changes on your store.
Want to modify or develop new app, Hire us.
If helpful then please Like and Accept Solution .
Shopify Apps URL :- https://apps.shopify.com/partners/zestard-technologies
Custom Modifications Into Shopify Theme | Shopify Private App | SEO & Digital Marketing