1.
class MyHelper extends Helper {
constructor(prop) {
 super();
 const {I} = inject(); → "I" is undefined
}
....
2.
class MyHelper extends Helper { 
myMethod = message => {
 const {I} = inject(); → "I" it is not the same instance being used in the context of step execution
};
.....
3.
class MyHelper extends Helper
{
async _before() {
 const {I} = inject(); → "I" it is not the same instance being used in the context of step execution
};

codecept.conf.js:
...
module.exports = {
 name: 'project',
 tests: '../src/tests/**/*_test.js',
 output: '../output',
 bootstrap: null,
 helpers: { 
 MyHelper: {
 require: '../src/lib/helpers/MyHelper.js',
 }
 },
......