Hi jatin,

Please refer below code:
Aura component:-

<aura:component controller="AttachmentController" implements="flexipage:availableForRecordHome,force:hasRecordId" 

access="global" >
    <aura:attribute name="recordId" type="String" />
    <lightning:fileUpload label="Attach Picture"
                name="fileUploader"
                multiple="true"
                accept=".pdf, .png, .jpg"
                recordId="{!v.recordId}"
                onuploadfinished="{!c.handleUploadFinished}" />
</aura:component>


Controller class:


public class Attechment {
    @AuraEnabled
    public static void updatePicturePath(String recId){
        //In Lightning Experience, Attachments are stored in ContentDocuments
        ContentDocumentLink docLink = [ SELECT ContentDocumentId
                                       FROM ContentDocumentLink
                                       WHERE LinkedEntityId = :recId order by Id desc Limit 1];
        //ContentVersion Id uniquely identifies the attachment
        ContentVersion ver = [SELECT Id FROM ContentVersion Where ContentDocumentId = :docLink.ContentDocumentId];
        //Update the Picture_Path field with the url of the image
        Student__c speaker = [SELECT Id FROM Student__c WHERE Id = :recId];
        speaker.Picture_Path__c = '/sfc/servlet.shepherd/version/download/'+ ver.Id;
        upsert speaker;
    }
    
}



Handler js file:-

({
    handleUploadFinished: function (component, event) {
        // Get the list of uploaded files
        var uploadedFiles = event.getParam("files");
        //set action to call updatePicturePath method from Server-side controller
        var action = component.get("c.updatePicturePath");
        action.setParams({
            recId : component.get("v.recordId")
        });
        action.setCallback(this, function(a){
            if(a.getState() === "SUCCESS"){
                var resultToast = $A.get("e.force:showToast");
                resultToast.setParams({
                            "title": "Success!",
                            "message": uploadedFiles.length + "file uploaded successfully."
                        });
                resultToast.fire();;
            }
        });
        $A.enqueueAction(action);
    }
})




I hope you find the above solution helpful. If it does, please mark as Best Answer to help others too.

Thanks and Regards,
Deepali Kulshrestha
www.kdeepali.com