If you view this page with the LanaPixel font installed, you will be able to see the various controller button glyphs, which are mapped in the Private Use Area of the font. You can use these symbols by copy+pasting them. If you need the Unicode value, you can see it by hovering over the symbol.
Feel free to use these to display controller inputs in your game! These probably aren't as good as full-colour button sprites, but perhaps they'll suit your needs.
OutlineFilled
Right
Left
Up
Down
R Stick
L Stick
R Stick H
L Stick H
R Stick V
L Stick V
PS Triangle
PS Square
PS Circle
PS Cross
PS Start
PS Select
PS R1
PS R2
PS R3
PS L1
PS L2
PS L3
PS Touchpad
XB A
XB B
XB X
XB Y
XB RB
XB RT
XB LB
XB LT
XB View
XB Menu
Switch A
Switch B
Switch X
Switch Y
Switch +
Switch -
Switch R Press
Switch L Press
Switch Home
Switch Share
Swich ZR
Switch R
Switch ZL
Switch L
Arrows: ←↑→↓↔↕↖↗↘↙