In the equation mode, input TeX commands such as \alpha□ , \sqrt{3}□, \x_1^2, \3□/ 5□. □ is space.
<Source:https://mathphysnote.com/msoffice/powerpoint-tex/, https://cyanatlas.hatenablog.com/entry/2018/05/19/021501>
Initial setting: Select Insert -> symbol -> equation to enter math-mode. (or just press alt +; to enter the math mode.)
Open the math option by clicking the very small arrow at the right bottom corner of the "tool" section at the left top.
Press the Math AutoCorrect button.
Input \TeX in the "replace word" section and input Ⓣ at the "replace with" section. Ⓣ can be input using 24C9 alt+x.
Input \LF in the "replace word" section and input Ⓛ at the "replace with" section. Ⓛ can be input using 24C1 alt+x.
Usage: In the math mode, enter \tex mode by pressing \TeX+ space. Before entering the \TeX mode, you need to input some character, for some reason.... Exit the TeX mode using \LF. To enter the math mode in my environment, press alt + N, E, then return. Erase the example equation, and input your own equation. Or, alt+N, X, I, then click the place you want insert the equation, and alt+N, E, I. The second one takes too much steps.
Input example: \alpha□ , \sqrt{3}□, \x_1^2, \3□/ 5□