Unexpted token '{' realpath in commands.sh

[shipsywor]

> node ./node_modules/cloudflare-docs-engine/bin/commands.sh bootstrap

D:\docs-engine-example\node_modules\cloudflare-docs-engine\bin\commands.sh:4
realpath() {
           ^

SyntaxError: Unexpected token '{'
    at wrapSafe (internal/modules/cjs/loader.js:979:16)
    at Module._compile (internal/modules/cjs/loader.js:1027:27)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
    at Module.load (internal/modules/cjs/loader.js:928:32)
    at Function.Module._load (internal/modules/cjs/loader.js:769:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:72:12)
    at internal/main/run_main_module.js:17:47

This happens when trying to do npm run bootstrap

OS: Windows 10
CMD: Git bash

How to fix this?