admincli.py check - error OPA Binary not found

Trying to follow some advanced commands in the tutorial -

(env) D:\osdu\admincli\cli>python admincli.py check tests/example.rego -t

The tutorial shows this:

Reading contents of tests/example.rego as 'example.rego'
Reading... ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 130/130 bytes 0:00:00

example.rego: OK

But when I try I get this:

Reading contents of tests/example.rego as 'example.rego' Reading... ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 135/135 bytes 0:00:00

example.rego: error OPA Binary not found

Is this intended ?