Joining multiple Table using sequelize

Question

I have 4 table t1,t2,t3,t4 in a POSTGRESQL database. Each of the table contains 3 common field, "currency" eg INR DOLLAR etc, "debt" eg 12006 , "credit" eg 1000. Credit and debt are integers. Each table contains multiple entries of every currency possible

I want the sum of debt and credit of each currency across all the 4 tables

currency	debt	credit
INR	12006	1000
DOLLAR	50002	3012
yen	1234	12546

I'm using sequelize, there's no realtion between any 4 tables, I'm only able to add credit and debt of 1 table at a time using this

var a = await asset.findAll({
            attributes: ['currency',[sequelize.fn('SUM', sequelize.col('credit')),
                         'credit'],
                         [sequelize.fn('SUM', sequelize.col('debt')), 'debt']
                       ],
             group: ['currency'],
        });

can someone please guide me how can I make a complete outer join using sequelize preferably else raw query would also work