Take a look at this:
Go to https://development.salesforce.com and log in to the developer site > Get Salesforce KEY and SECRET. Click "Your Name" in the upper right corner to expand the drop-down menu, then click My Developer Account and log in to your developer account > Click "Your Name" in the upper right corner to expand the drop-down menu, then click Setup > Find the Build section in the left column, then click Create in the lower right corner to expand the hidden menu > Locate and select Apps from the hidden menu (not in the right column) > Locate the Connected Apps area at the bottom of the right column, then select New > To obtain Keys, fill up the required information.
Hope this helps!
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Thanks!