' get the body tag
Private body As BANanoElement
body.Initialize("#body")
Dim varID As String = "myiframeid"
Dim mSrc As String = "https://b4x.com"
Dim mWidth As String = "100vw"
Dim mHeight As String = "100vh"
' append the iframe tag
body.Append($"<iframe id="${varID}" src="${mSrc}" width="${mWidth}" height="${mHeight}" frameborder="0"></iframe>"$)
If you want to be serious about working with BANano you should really read the booklet because creating tags is very basics. You must understand at the very least what BANanoElement and BANanoObject are.