Mermaid.js with Node.js - Dynamically generation

Question

I am working with Mermaid.js to general a Class Diagram for my hobby project.

I am facing a very basic issue, which I cannot figure out how should I approach it.

Basically, I have the structure generated, but when I push it to the view, it is rendered with double quotes and also the '\n' is showing as well.

Node.js

let unique_Object = _.groupBy(json_result,'ChildRelationship')
let chart_schema = "classDiagram\n"
Object.keys(unique_Object).forEach(function (item){
   chart_schema = chart_schema + objectName + " <|-- " + item + "\n"
})

return chart_schema

Koa Route

.get('getD', '/getD', async (ctx) => {
   try {
      const result = await util.get_childRelationship()

      return ctx.render('test',{
         object: result
      })
   } catch (error) {
      console.error(error)
   }
})

View

<div class="mermaid" id="mermaid">
    <%- chart %>
</div>

<script src="https://cdnjs.cloudflare.com/ajax/libs/mermaid/8.4.4/mermaid.min.js"></script>
<script> mermaid.mermaidAPI.initialize({
    startOnLoad: true
});</script>

View Result

"classDiagram\nParent <|-- Joe\n"

The browser is ignoring the \n.

If anyone has any idea?