Logical control of presence of a tab in quarto document

Trying to control which tabs are available in a quarto document. The following shows what I am attempting but does not work as tabs are not actually created.

---
title: "Tab Test"
format: html
editor: visual
---

```{r}
#| echo: false
#| include: false

# Tab control

Tab1 <- TRUE
Tab2 <- FALSE
Tab3 <- TRUE

Start the tabs

{.tabset .tabset-pills}

#| echo: false
#| include: true
#| eval: !expr Tab1
#| results: asis

# Print the tab

cat('### Tab1\n\n')
cat('Content for Tab1.\n\n')

#| echo: false
#| include: true
#| eval: !expr Tab2
#| results: asis

# Print the tab
cat('### Tab2 \n')
cat('Content for Tab2.\n\n')
#| echo: false 
#| include: true
#| eval: !expr Tab3
#| results: asis
 
# Print the tab 
cat('### Tab3\n\n')
cat('Content for Tab3.\n\n')
cat('\n')

This is the output. Hard to see without the html, but I get headers but they are not active tabs.

Tab Test
Start the tabs

Tab1
Content for Tab1.

Tab3
Content for Tab3.