Missing 'Add Shortcut' button on Google screen in Chrome on iMac

i am using google chrome on my imac desk computer. i want to add a shortcut to a travel site on the google screen . i watched several videos and the say there should be a plus sign + that says add shortcut . i do not see any plus sign . i went to chrome share and created a shortcut but it appears on my dektop not on the google screen can anyone help me maybe my computer is too old

[Re-Titled by Moderator]