If you're interested in DIY-ing a M34063 5V to 12V boost converter, you might want to check out this article.

If your multimeter battery drains quickly and often needs replacing, you can follow this guide to make a boost converter yourself. You'll need to gather some parts: resistors, capacitors, an inductor, and the M34063.

The circuit diagram looks like the one below, with the output on the left and the input on the right.

First, you need to lay out the wiring according to the schematic. Then use a rectangle tool to cover the points that connect together, so you get a diagram like the one below.

Second, print the board according to the diagram. Set both the length and width to 2.54 cm, which fits perfectly. Once it's printed, you can stick it onto the board and then carve it out with a knife.

Third, you need to do the soldering. Once it's done, the boost converter should output 12V. If you don't have a 100pF capacitor, you can use five 22pF ceramic capacitors in parallel. If the inductor breaks, you can connect a 100μH and a 33μH in series. If you don't have a 200Ω resistor, you can use two 100Ω resistors in series, and for a 1.2kΩ resistor, you can use two 560Ω resistors in series. Just be flexible with the parts you have.

Fourth, put all the components into a box, drill a hole, attach a USB cable, and then you can power it with a Xiaomi power bank.

Done.