Getting UIPanelButtonTemplate texture

[Benalish]

I created a SecureActionButtonTemplate in this way

local main = CreateFrame("Frame", nil, UIParent)
main:SetSize(450, 250)
main:SetPoint("CENTER")
main.button = CreateFrame("Button", nil, main, "SecureActionButtonTemplate")
main.button:SetSize(32, 32)
main.button:SetPoint("CENTER", main, "BOTTOM", 0, 40)
main.button:RegisterForClicks("AnyUp")
main.button:SetAttribute("type", "macro")
main.button:SetAttribute("macrotext", "/stopcasting")

Now I would like to give this button the same texture as the UIPanelButtonTemplate, and maybe even set some text.
How can I do?