In Yahoo Mail, select the gear icon  in the upper-right corner

A pop-up will appear under Settings, scroll down and click More Settings

Click Mailboxes and choose the email account you wish to add / edit your signature

Toggle on the Signature switch

In the text box below you can type in your signature 

Highlight what you want hyperlinked to your digital business card (Ecard URL)

With your text highlighted, click the hyperlink icon from the toolbar

Copy / Paste your Ecard URL into the Address text-field (https://ecard.covve.com/yourpersonalizedecardurl)

Click Save to save your signature!