How to assemble ARM instructions (using GCC)

I want to assemble ARM instructions (= converting the textual assembly instructions to machine code).

I tried using IDA Pro to disassemble an ARM binary but upon assembling it told me:

Sorry, this processor module doesn't support the assembler.

Then I downloaded an ARMgcc but trying to assemble with it also fails:

>gcc-arm-none-eabi-9-2019-q4-major-win32\arm-none-eabi\bin\as asm.s -o asm.oasm.s: Assembler messages:asm.s:1: Error: ARM register expected -- `mov W8,#0x80'

Why is the syntax invalid when IDA Pro shows instructions exactly like that?Does this gcc not support this ARM dialect or do I need a certain command line switch to make it work?

Processor       : ARMARM architecture: metaarmTarget assembler: Generic assembler for ARMByte sex        : Little endian