It can be added in two ways.
1.- replace the flow_boot.erp file in the F1 2020\2020_asset_groups\ui_package
2.- Modular Mods can be used.
Modify the flow_boot.assetgroup file as follows
<?xml version="1.0" encoding="utf-8"?>
<!--This file was automatically generated-->
<AssetGroup bigERP="true">
<ERP>_Modular_Mods/_ACTIVE/start_screen.erp</ERP>
<ERP>_Modular_Mods/_ACTIVE/flow_boot.erp</ERP>
</AssetGroup>
save the changes.
Then copy the file flow_boot.erp into the _ACTIVE
Can be used freely or in any Mod.
