D3 geo Projection

<%= @topic_view.topic.title %>
<%= @topic_view.topic.average_rating %> <%= @topic_view.topic.posts.count { |p| !!p.custom_fields['rating'] } %>

Well, I working on choropleth Map but having problem with d3-geo-projection. I’m using d3 version 5 and
usecase:

d3.geoPath().projection(d3.geoEquirectangular());
It shows nothing other than big rectangle shape, but if projection is omitted than topojson map is visible.
What am I missing.