A warm hello to you Anna,
Apologies for the late reply. I’m not sure if anyone has replied to your question yet? Apologies again if someone has.
I believe you can get some SM Credits when you open the Free Pack tab at the bottom left of the Overview screen. I am 100% sure you receive them as I currently have 224 and that’s without me spending a single penny. Every four hours you can open the Free Pack and this gives you extra funds, Points etc. There prob isn’t another way to add SM Credits other than by purchasing them. Hopefully the more you play, the more you can add via Free Pack. By not adding free SM Credits to the game, it would be harsh on everyone that plays the game by making people pay for them.
I hope this helps answer your question? And I hope your enjoying the game? For a free game I think it’s addictive, not sure if you agree Anna? If only they would include other teams buying other players and making subs. Any other questions then feel free to ask me. Enjoy.
Take good care, enjoy your weekend,