my_file.xml

<xml xmlns="https://developers.google.com/blockly/xml">
  <variables>
    <variable id="dO}ep_BBC;jSo=%2.gVR">VAR</variable>
  </variables>
  <block type="variables_set" id="G75t?g1d=xcy8SqklXUd" x="312" y="88">
    <field name="VAR" id="dO}ep_BBC;jSo=%2.gVR">VAR</field>
    <value name="VALUE">
      <block type="text" id="wT?_Zq%kO]8z|5)5_tQY">
        <field name="TEXT">JK</field>
      </block>
    </value>
    <next>
      <block type="controls_repeat_ext" id="$;.6=])r*pTA`rx8@H;K">
        <value name="TIMES">
          <shadow type="math_number" id="_(}ol~k4w#L$d^uxS%w=">
            <field name="NUM">10</field>
          </shadow>
        </value>
        <statement name="DO">
          <block type="my_custom_block" id="2">
            <field name="MY_FIELD">1</field>
            <value name="MY_VALUE">
                <block type="text">
                    <field name="TEXT">JK</field>  
                </block> 
            </value>
          </block>
          
        </statement>
      </block>
    </next>
  </block>
  <block type="text" id="J54OJ7(NVpC:=#L=p=^9" x="612" y="238">
    <field name="TEXT"></field>
  </block>
</xml>