It is one of two things. Either your role does not include that area or the feature is not part of your plan or product line.
Telling them apart
If somebody else in the business can see it and you cannot, it is your role. If nobody can see it, it is the plan.
Features that depend on a plan or product line
- Classes need group bookings

- Workshop, Vehicles, Parts, Suppliers, Purchase orders and Part requests need Garage Pro
- Leave & Holidays needs staff leave management
- VAT & Tax Returns appears once VAT is enabled for your account

If it is a permission
Somebody with settings access can adjust the role under Team, then Roles & Access. After a change, sign out and back in if the menu has not caught up.

If it is a plan
Check Settings, then Plan & Billing, to see what your plan includes.

Common questions
I upgraded and still cannot see it. What now?
Sign out and back in. If it is still missing, contact support with the feature name.

Why is the workshop missing when I run a garage?
The workshop is part of Garage Pro rather than the standard product line.

Can I try a feature before paying for it?
Ask support. It is a better use of your time than guessing from a pricing page.