Add the Generate Quote from Resource Hero button to the Opportunity Lightning Actions

From the Opportunity page layout edit screen, click the override the predefined actions link from the Salesforce1 and Lightning Experience Actions section.

From the top panel, select Salesforce1 & Lightning Actions from the left side, then drag the Generate Quote from Resource Hero button to the Salesforce1 and Lightning Experience Actions section, then click the Save button.

The Generate Quote from Resource Hero button is now available from the Light actions at the top right of the Opportunity page.