Is it valid to divorce a wife over the phone, via text messages, or voice messages, before consummating the marriage, knowing that the marriage contract has not been registered with the court?

Divorce takes effect either by the husband uttering it or writing it with the intention of its occurrence, whether the wife hears it or not, and whether she is present or absent. It is recommended to have witnesses for it, and some scholars are of the opinion that it is obligatory. One should refrain from divorce if possible.