Husband changed number while being legally married

Hi. I have been married for few years. My husband was a green card holder Indian citizen during the time of marriage.Our marriage is not registered as he said he will do it after the citizenship. Last year he got his citizenship after that he started threatening me divorce. But still 2 times after that he met me and said he wants the marriage. Few months back he changed his phone number and even his parents who reside in india claim that they don't know his number. His parents are currently in india only due to covid. Once the international flights start they will also go to usa. After that I will never be able to find him. I just want to know what are my options here to claim maintenance from Him as over the years he hasn't taken care of me or given me even the basics and also to know is it legally okay he changed his number while being married to me and neither he or his family are giving it to me.can I file a complaint against the parents for refusing to tell me where my husband is. Is there a way I can prevent his parents from leaving the country. As once they leave I will never be able to find my husband as he is a usa citizen. Kindly advise In the years of marriage I have been put through immense torture.