You need to use the VNode data type in the seq. This is a working example:
include karax / prelude
var elements: seq[VNode] = @[]
proc createDom(): VNode =
result = buildHtml(tdiv):
button:
text "Say hello!"
proc onclick(ev: Event; n: VNode) =
let node = buildHtml(tdiv):
h1:
text "Hello!"
elements.add(node)
for element in elements:
tdiv:
element
setRenderer createDom