Power BI Dashboard reporting

Hi, We are a UK company of about 30 users using Microsoft 365 and Sharepoint online as our core business tools (plus Azure for 365 Auth), but we have very basic BI reporting that needs improving and don't take advantage of all the tools and integrations that Microsoft provide. We build and host our own integrated java based applications which include ERP, E-commerce & Private reserves that run on a single Postgres database, this where the CRM/business/ordering data is inputted & generated. I have created a standalone reporting server with the database log-shipped from production so we have good resource overheads for reporting. Within our ERP we have a number of key reports used to run the business that are used in very manual fashion (i.e. set date range and a few parameters and then d/l a static spreadsheet) and there is little or no data visualisation apart from a basic Postgres > Power Query > Power BI project that I started a year ago, but haven't finished it as other tasks took priority over my and my developers time and I actually reached the limit of my knowledge. I have connected Power query to Postgres and I have already extracted and catalogued the key queries behind the key reports in our ERP into a Sharepoint directory and started building a Data Catalogue in Power Query, but this Data catalogue doesn't appear to be available in Power BI, so I got stuck (and I still can't understand why MS doesn't allow these products to integrate easily?). I also don't have the knowledge of experience to build a suite of reports and dashboards for our different users: Sales Account Managers, Purchasing, Sales & Stock Analysis etc... I have been approached with other BI solutions, but I feel that we should take advantage of the Microsoft tools and infrastructure we already have at hand (and pay for with our licences). With the right expertise (and a little interaction with our java developers to iron out any issues with the baseline queries or create new ones) I think a set of high quality reports and visualisations could be built relatively quickly as the data and infrastructure is already there. Kind regards, Edward