To save time, set up an allowed email domain so that anyone with a matching email (e.g. @example.com) can join your workspace without a manual invite or approval.
Go to Settings > Authentication and edit the Authentication provider, e.g. Google.
Provide a comma-separated list of which e-mail addresses to allow. To allow all email addresses under a certain domain/e-mail provider, such as any email address that ends with @edu.cn, write either simply the domain name (e.g. edu.cn) or an asterisk followed by an at-sign, followed by the domain name (e.g. *@edu.cn). Leaving this field blank allows all email addresses.