Understand what are your monthly limits (all roles).
To check what is your current approval policy:
Head over to your Profile by clicking on your Avatar in the top right-hand corner
This should give you an idea of:
how much you can spend in one transaction without approval.
how much you can spend in one month without approval.
on which payment methods this rule applies.
If you are an Account owner, you don't have any approval policy.
You need the Requester role to be able to have an approval policy. If it's not stated in your roles, contact your admin.