I am trying to add page in SharePoint Online but page layout (Welcome Page) Search People is not showing up among the options.
Is it some SharePoint Feature that I need to activate to get the page layout?
You need to activate the following site collection feature:
Search Server Web Parts and Templates This feature will add the Search Server Web Parts and Display Templates to your site. Search will work on most sites without this feature being activated, but if you get a message about missing templates when searching, then activate this feature.
The layout should be available after you activate this. If not, check the Page layouts and site templates page under site settings. The site could be configured to only use certain page layouts.
-Hope it helps
Thanks Rodirgo, your suggestion helped.
and in the mean time I get another workaround:
this link also provide solution.