There are many ways to trigger an Email Flow:
Via Webhook
Watch demo here: https://www.youtube.com/watch?v=Op5Q2Tr6WYI
Via Shop Notifications:
Watch demo here: https://www.youtube.com/watch?v=OjSO3ENHWN0
Via Chatbot Actions element (Applicable for Messenger, Instagram, WhatsApp and Google Messages)
Learn how to configure an action element here: https://docs.marketingmaster.io/article/375/chatbot-flow-action-element
Via Custom Landing Page
Go to Email Marketing → Landing Pages → Create or Edit your Landing page → Configure Landing page “Settings” → Set Email flow
Via Custom Forms
Go to Email Marketing → Custom Forms → Open HTML Code → Assign Emai Flow → Copy HTML code and paste on your Website