Opt In or Out of Multi Asset Collateral

curl --request POST \
  --url https://api.coinbase.com/api/v3/brokerage/intx/multi_asset_collateral \
  --header 'Content-Type: application/json' \
  --data '{
  "portfolio_uuid": "<string>",
  "multi_asset_collateral_enabled": true
}'

{
  "multi_asset_collateral_enabled": true
}