For accounts (this returns pages of 100 at a time):
https://chapman.crmcloud.infor.com/sdata/slx/dynamic/-/accounts?format=json

For a specific account: ("A4CHTA0025F7" is the account record ID)
https://chapman.crmcloud.infor.com/sdata/slx/dynamic/-/accounts('A4CHTA0025F7')?format=json

Similarly, for a contact, you could replace "accounts" with "contacts":
https://chapman.crmcloud.infor.com/sdata/slx/dynamic/-/contacts?format=json

Or a single contact:
https://chapman.crmcloud.infor.com/sdata/slx/dynamic/-/contacts('C0N53A00002S')?format=json