Issue with null values in xml data

[uiit3155]

How to fetch data of xml which has below format?

<tpDirectConstructionLocal xsi:nil="true" />

I am getting below error while using  xpath(xml(outputs('Compose_3')), 'string(//tpDirectConstructionLocal)')

The 'inputs.parameters' of workflow operation 'Create_item_2' of type 'OpenApiConnection' is not valid. Error details: Input parameter 'item/marketingBasisDocAvailable' is required to be of type 'Boolean'. The runtime value '""' to be converted doesn't have the expected format 'Boolean'.