Is receiving a dinar in exchange for inviting friends to download a banking application via a special code considered unlawful (haram)?

If the application belongs to an Islamic bank that adheres to Shariah principles, then there is no harm in downloading it, inviting people to it, and benefiting from what one earns from it, because it falls under the category of permissible brokerage in lawful matters. However, if it belongs to a usurious bank, then it is not permissible to invite people to it or earn from it, due to the cooperation in sin involved therein.