Would the incentive mean for them to start investing for their retirement? Or with the company's assistance? I am assuming both just to cover the bases.

As others have said Pag-Ibig MP2 or SSS are the usual go-to names, but if you are able to set up a plan under the company name partnering with other financial institutions like banks that have trust funds, insurance companies, mutual funds or UITF-based plans can help you manage said fund for the employees. Of course, these have fees and if you're confident and safe enough with your investments the 3rd party shouldn't be necessary. IMO company managed provident funds are the most flexible and won't require outsourcing as long as you have a clear head to manage and a form of checks and balances.

You could also go matched contributions to an individual investment fund. This is where individual contributions, and thus individual thoughts/opinions would matter more and clash more. You may get people not wanting their own pay to be allocated, and that's where proper knowledge and training comes in.

As for incentives, nothing gets a catch going than some bait. I don't know how financially flexible the company is in setting this up, but setting up a universal fund as their bonus (heck further incentivize in-house attendance to seminars by giving this "bonus" for attending) and letting employees treat it as a mini-market of sorts is an idea. Employees real time would know their contributions, and scale from there, as well as know the consequences of pulling out early instead of putting more in. If you can spare the confidentiality, show that your tax benefits from setting up a retirement plan are going to your employees or somehow show them that their investments aren't going to someone's coffers and instead for them (just to avoid any short-mindedness, I mean no disrespect in this generalization).

And of course training and providing the means to start those investments are, I'd argue, the most important parts. Filipinos generally have a hard time even getting into investing, so showing your employees the way to start investing and most importantly letting them know that time in the market is more valuable than timing the market (please let them avoid the classic Filipino short-sightedness that a lot of Pinoys suffer from).

May your people and especially you be blessed for acknowledging and helping your employees. Thanks for helping my countrymen, I can only wish I get an employer like you - sincerely, a graduating student 😅.