I do not understand your question

do you mean how long. well I read in soneplaces it takes about a year or more. due to the virus

I think, they do it in 3 months and then the case is transferred to consulate

ohh that’s through. 3 months I didn’t understand

When the I-130 is approved, the Case is transferred to National Visa Center. NVC takes about 3 months to look at the documents that you provide to make sure everything is there and correct. After that, they schedule your interview with the Consulate.

how long they schedule for interview nvc can you tell me please

depends on your country. as at now it takes one year and more.

that’s too long but my country is take 1 month only