How to get Entity Reference View field value/target_id Programmatically

Problem/Motivation

I have created a content type Delivery Challan
In that content type i have made a field of entity reference view field_po_amendment_ref
this field works perfectly and reflect values on this field on front end
BUT
I am not able to get value of this field pro-grammatically, I need get and set this field programattically after Node::load
I am not able to even see this field in node load dump
#values: array:23 [▼
"nid" => array:1 [▶]
"vid" => array:1 [▶]
"type" => array:1 [▶]
"uuid" => array:1 [▶]
"langcode" => array:1 [▶]
"revision_uid" => array:1 [▶]
"revision_timestamp" => array:1 [▶]
"revision_log" => array:1 [▶]
"revision_default" => array:1 [▶]
"isDefaultRevision" => array:1 [▶]
"status" => array:1 [▶]
"uid" => array:1 [▶]
"title" => array:1 [▶]
"created" => array:1 [▶]
"changed" => array:1 [▶]
"promote" => array:1 [▶]
"sticky" => array:1 [▶]
"default_langcode" => array:1 [▶]
"revision_translation_affected" => array:1 [▶]
"field_dc_date" => array:1 [▶]
"field_dc_li" => array:1 [▶]
"field_dc_status" => array:1 [▶]
"field_po_ref" => array:1 [▶]
]
please help

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes