くれば

if ... and come back

→ 来る
くれ come; arrive + ば Conditional (“if”)
auxiliary · informal Rare #33,283
if ... and come back Used after a verb in the て-form, as in 見てくれば (if you go and take a look).
JA: 駅まで行ってくれば?
EN: Why don’t you go to the station and come back?
Conjugation of 来る

行って見てくれば?

Why don't you go and see for yourself?

なら行ってくれば

Then go ahead and go.

— ブエノスアイレス (1997)

ワインもう一本買ってくればよかったね。

We should have bought another bottle of wine.

ちょっと散歩してくれば朝食がおいしく食べられるでしょう。

If you go for a short walk, you’ll probably enjoy your breakfast more.

もう一枚着てくればよかった。

I should have worn one more layer.

死体で持ってくれば賞金が出る

Bring him back dead, and there’s a reward.

— RRR (2022)