How to type pinyin text with tone marks in Windows?

The U.S. international keyboard that comes with Windows makes typing some accents easy, but apparently not macrons (the bar over the "u" in "chū"). The Māori keyboard has support for those; maybe you can hot switch between the two? Someone claimed to have made a derivative of the international keyboard that permits typing the macrons as well as other accents easily, but I haven't tried it out.

You could try using a tone converter that takes in numeric-based tones and spits out accent-based tones.

Edit:

I found an explicitly pinyin keyboard layout that should do what you want.

May I suggest my own PinyinTones IME, which does exactly what the OP was looking for:

• https://www.pinyintones.com/

It's a Windows IME that outputs Pinyin with tone marks, rather than Chinese characters. Type 1, 2, 3, or 4 after each syllable to add a tone mark -- just as people have been entering Pinyin since the days of ASCII characters:

Key features:

1. Uses the Text Services Framework, so it works everywhere that the Microsoft Pinyin IME works. Including desktop and Universal applications.

2. Uses in-line text composition, just like the Microsoft IMEs. This means that it behaves well in TSF-aware applications -- for example, when inserting, text will reflow as you type.

3. Automatically places tone marks on the correct vowel in a combination, according to the rules of Pinyin orthography. (e.g., hao3 becomes hǎo -- with the tone mark on the "a" rather than on the "o")