Learn Croatian: Inspektor je naredio da ovdje donesemo opremu. - The inspector ordered that we bring the equipment here.

In Croatian, reported commands and requests are formed using da followed by the present tense, even if the order was given in the past. The present tense here expresses the action that is expected to happen, rather than when the inspector actually spoke.

I learned that perfective verbs like donijeti (to bring) aren't normally used in the present tense. Why is it used here?

While you cannot use perfective verbs to describe ongoing actions happening right now, they are perfectly normal in the present tense after da when expressing a completed goal, wish, or command. Donesemo shows the inspector wants the action of bringing the equipment to be fully completed.

The infinitive is donijeti. Why does the spelling change so much in donesemo?

Donijeti is an irregular verb. In the present tense, its stem changes to dones-, which is why the "we" form is donesemo. This is a highly useful pattern to memorize because it applies to all verbs ending in -nijeti, such as odnijeti (to take away), which becomes odnesemo.

How does ovdje (here) pair with the choice of verb?