First, you will need to select what event, or trigger, starts your flow.

  1. In, select My flows in the top navigation bar, and then select Create from blank.

    Flows option in the left navigation bar

  2. Select the Search hundreds of connectors and triggers box at the bottom of the screen, enter Twitter in the box that says Search all connectors and triggers, and then select Twitter - When a new tweet is posted.

    Twitter event

  3. If you haven't already connected your Twitter account to Microsoft Flow, select Sign in to Twitter, and then provide your credentials.

  4. In the Search text box, type the keyword that you want to find.

    Twitter keyword

Source: Microsoft