No, it is possible to use financing. However, it is not possible to stipulate a special clause that says "the sales contract can be cancelled if the buyer is unable to use the financing". In other words, even if the buyer is unable to obtain financing approval after the purchase agreement is signed, the buyer must still pay the remaining amount.
Generally, in the case of a transaction where "no special agreement on loan" is a prerequisite, the buyer obtains loan approval from the financial institution requesting the loan prior to the conclusion of the sales contract in order to avoid payment of compensation for damages, etc. due to default to the seller.