To remove “Sign In”, you can follow these.
#1. All Pages
Edit Site HeaderClick ADD ELEMENTSDisable Account option
#2. One Page
First, find Page ID.Next, use CSS code like this to Custom CSS box.
#collection-66a1bfc99041e47b896c1e48 .user-accounts-link { display: none !important; }
#3. Desktop Only
Use this CSS code
div.header-display-desktop .user-accounts-link { display: none !important; }
#4. Mobile Only
Use this CSS Code
div.header-display-mobile .user-accounts-link { display: none !important; }
#5. On Header Scroll
Use this CSS code
header#header.shrink .user-accounts-link { display: none !important; }