Sample Code:

Lightning Web Component:

HTML:

<template>  
  
    <lightning-record-edit-form record-id="0013i000003DPlvAAG"  
                                object-api-name="Account"  
                                onsuccess={handleSuccess}>  
  
        <lightning-messages></lightning-messages>  
        <lightning-output-field field-name="Name"></lightning-output-field>  
        <lightning-input-field field-name="Industry"></lightning-input-field>  
        <lightning-input-field field-name="Description"></lightning-input-field>  
        <lightning-input-field field-name="Rating"></lightning-input-field>  
        <lightning-button class="slds-m-top_small"  
                          variant="brand"  
                          type="submit"  
                          name="update"  
                          label="Update">  
        </lightning-button>  
  
    </lightning-record-edit-form>      
      
</template>  

JavaScript:

import { LightningElement } from 'lwc';  
  
export default class AccountEditLWC extends LightningElement {  
  
    handleSuccess( event ) {  
  
        const payload = event.detail;  
        alert( JSON.stringify( payload ) );  
  
    }  
  
}  

Output: