CODE EXAMPLE FOR PHP

magento2 add static block in phtml

<referenceBlock name="my-main-phtml-block">    <block class="MagentoCmsBlockBlock" name="my-main-phtml-block-cms">        <arguments>            <argument name="block_id" xsi:type="string">my_cmsblock_identifier</argument>        </arguments>    </block></referenceBlock>