How to export and import class in javascript

I have write a class in a abc.js file. I need to import that class within a html file. for that i am using

export class myclass{
and import using  `import myclass from './abc.js' ;` But it shows the following error

> net::ERR_ABORTED 404 (Not Found) .  Please help me

Try with export default:

Thanks for your reply @JivkoJelev91. But that has been tried already. following error is occured sometime

Failed to resolve module specifier “data_management.js”. Relative references must start with either “/”, “./”, or “…/”.