Hello,
first you need to visit E-MAILiT website (https://www.e-mailit.com/widget/register) and create your account.
Sign in, add a domain (https://www.e-mailit.com/widget/control/add_domain) and get your Domain Verification Publisher Key.
Copy only the ”E-MAILiT_…” line and paste it in the E-MAILiT Share (WordPress) Settings/Plugin Options, first field on top of the page.
For example:
Domain Verification Publisher Key (E-MAILiT_…): E-MAILiT_F13486169905062431e46374
Press Save Changes.
Return in your E-MAILiT.com account and press the Verify button. Done. You are ready now to create your customized buttons.
Please, let us know if you need further assistance and clarifications.
best,
The E-MAILiT Team