Open Application with F19 hotkey on Mac by Hammerspoon

~/.hammerspoon/init.lua

-- after open outlook, switch the tab between mail and outlook calendar by (cmd+`)
hs.hotkey.bind({}, "f16", function()
  hs.application.open('Outlook.app')
  local outlook = hs.application.applicationsForBundleID('Outlook.app')
  hs.eventtap.keyStroke({"cmd"}, '`', outlook)
end)
hs.hotkey.bind({}, "f17", function()
  hs.application.open('Google Chrome.app')
end)
-- ctrl + f18
hs.hotkey.bind({"ctrl"}, "f18", function()
  hs.application.open('Terminal.app')
end)
-- ctrl + alt + f19
hs.hotkey.bind({"ctrl", "alt"}, "f19", function()
  hs.application.open('Calendar.app')
end)

Ref:

Hammerspoon docs: hs.application

Hammerspoon docs: hs.hotkey

Hammerspoon: continuously send keystrokes to one application, while using others normally