Importing csv file?

I would much like to purchase the pro version of Mailspring as it’s come along way since I last looked at it. However there is one last thing that is stopping me from finally taking the plunge. There seems to be no way to import my 2000+ contacts via .csv file (downloaded from Google).

I have removed my information from Google and now have all my contact info & calendar data on a private Nextcloud server. Unfortunately, I do not see any way of importing contact lists into Mailspring… Am I missing something?

I was also wondering can it if Mailspring would possibly be able to import from specific mail server contact lists? I thinking of mail servers like Zimbra & MailCow specifically.