How to send email alerts in MassMailer using the Salesforce Flow Builder l Mass Mailer

Thank you for the video! I would be grateful if you can answer my question. I have 2 objects in saleforce. A and B. A is master of B so A would have multiple B records under it. B record stores email. When some trigger happens on A I need to send emails for all B records. One way is to parse MassMailer - Email via MassMailer apex function in a loop in the flow and put B's record it one at a time in Record Id input parameter. This is working good. I am wondering if there is a way to use MassMailer - Email via MassMailer apex function for all the B records ids at once skipping the loop?