Firstly, all Employers are legally obliged to make a Personal Retirement Savings Account (PRSA) available to all employees. So they are required to have established a structure with some PRSA provider.
The Employer is not required to contribute, but they are required to facilitate you contributing via the "net pay" structure.
So maybe the starting point would be to approach your Employer and ask who he has set up the PRSA with (assuming he has such a structure in place). If he has not set up a PRSA facility, then you could advise him that he is legally required to do so.
So assuming you are prepared to contribute (the Employer must facilitate you doing so though payroll), the next stage would be to ask the Employer will they match your contribution. If push comes to shove you could agree to take a salary increase by means of a pension contribution.
Best of luck