There is any standard user for accountant who is only responsible for company cash or treasury
You can create Users and assign specific role to them. For accounts the default roles in ERPNext are Accounts Manager and Accounts User. You can specify the permissions for these roles from user permission manager.
Links to learn more on the same.
https://frappe.github.io/erpnext/user/manual/en/setting-up/users-and-permissions/adding-users
https://frappe.github.io/erpnext/user/manual/en/setting-up/users-and-permissions/role-based-permissions
https://frappe.github.io/erpnext/user/manual/en/setting-up/users-and-permissions/user-permissions
Hope this helps.