Step 1 : Open your Online Store
Log in to your Shopify admin. In the left-hand menu, scroll down to Sales channels and click Online Store. This is where all your themes live.
Step 2 : Go to the Import button
On the Online Store page, scroll down to the Draft themes section. On the right side, you'll see the Import button. Click the dropdown arrow next to it.
Step 3 : Upload your theme ZIP file
From the dropdown menu, click Upload zip file, then select the theme .zip file you downloaded after purchase. Shopify will upload and add it to your draft themes usually within a minute.
