The Assessment Parcel layer provided by the LIO online mapping application is, it seems, not intended to be accessible outside the application. As noted by a commenter, the usage rights of that application explicitly prohibit scraping data.
I believe this is related to the complicated relationship Ontario has with Teranet, the private entity to whom it has (somewhat controversially) outsourced management of property ownership records and their digitization. Teranet charges people money for access to this data. See breadcrumbs regarding the access limitations alluded to at https://geohub.lio.gov.on.ca/documents/lio::ontario-parcel-ownership-parcel/explore
You can access a variety of LIO data freely and legitimately if it is part of the
LIO_OPEN_DATA collection. As discussed in the instructions at https://www.sdc.gov.on.ca/sites/MNRF-PublicDocs/EN/CMID/LIO-OpenDataService-UserGuide.docx these can be accessed as a REST service at https://ws.lioservices.lrc.gov.on.ca/arcgis1071a/rest/ (note the server is 1071a not the 1061a used by the mapping application) and navigating to
LIO_OPEN_DATA and its subdirectories
LIO_Open10 there. In
LIO_Open06 you will in particular find "Lot fabric improved", which is not ownership/assessment parcels but will get you part of the way there in rural areas.
Many Ontario counties, municipalities, and townships, as well as Conservation Authorities, have their own GIS systems with REST servers. Many of them include clipped versions of the Assessment or ownership parcel layers, often without token required. It is hard for the common user to figure out the intended access restrictions on these layers since metadata is often very limited.