You can add below code in you xml or
<referenceBlock name="breadcrumbs">
<action method="addCrumb">
<argument name="crumbName" xsi:type="string">home</argument>
<argument name="crumbInfo" xsi:type="array">
<item name="title" xsi:type="string" translate="true">Home</item>
<item name="label" xsi:type="string" translate="true">Home</item>
<item name="link" xsi:type="string">/</item>
</argument>
</action>
<action method="addCrumb">
<argument name="crumbName" xsi:type="string">myaccount</argument>
<argument name="crumbInfo" xsi:type="array">
<item name="title" xsi:type="string" translate="true">Your Custom Page</item>
<item name="label" xsi:type="string" translate="true">Your Custom Page</item>
<item name="last" xsi:type="boolean">true</item>
</argument>
</action>
</referenceBlock>
If you have created cms PAge then u can add it in "Layout Update XML" field or u can use below settings for enable breadcrumb in ur cms page set it as yes.