When importing statements the payment didn't link with the purchase entered

when importing statements the payment didn’t link with the purchase entered so now it looks like I haven’t paid a purchase but in my cheque account there is a payment for the same amount and under
the same account (ie insurances)

If you import your bank statement, you will end up with duplicates of transactions you already entered. The purpose of imports is that you don’t need to enter transactions. So delete one or the other.

If you are using the importing statements as the payment for the purchase then the Account for the imported transaction should be Accounts Payable + Supplier + Invoice. However, if you had previously done a Spend Money then delete the imported transaction as advised above